1. Field of the Invention
The present invention is generally related to a clamp which secures apparatus, such as an end-of-train marker light and telemetry equipment, to the coupler head of the last car in a train and, more particularly, to a railroad coupler clamp which secures equipment to the guard arm side of a coupler head.
2. Description of the Related Art
As is well known in the art, apparatus such as end-of-train signaling equipment is commonly used to meet modern railroad operating and safety requirements. Various train operating parameters (e.g., brakeline pressure, and the like) are remotely monitored by the end of train equipment, and telemetered to an engineer in the locomotive cab. In addition, the end-of-train equipment can include a marker light to identify the end of the train.
Over the years, several railroad coupler mount configurations have been devised for securing the end-of-train signaling and monitoring equipment to the coupler head of the last car in a train. U.S. Pat. Nos. 2,355,544 to McGowan and 4,487,060 to Pomeroy show signaling and monitoring equipment positioned inside the coupler head. Positioning the equipment within the coupler head is not ideal since it can be damaged by accidental mating with a coupler of another car, a situation which is likely in an active yard. Moreover, pusher locomotives cannot be connected without first removing the equipment. U.S. Pat. No. 4,592,217 to Fernandez et al. shows mounting the equipment on top of the coupler head by using a flag hole. This arrangement avoids accidental equipment damage; however, the arrangement has the disadvantage that not all coupler heads include a flag hole.
In the related art, most railroad couplers used in the United States and Canada are cast with four relief holes, or core holes, in the guard arm side of the coupler head. FIG. 1 shows a typical coupler head 10, used in the United States and Canada with two uppermost core holes 12a-b which are spaced vertically from two lowermost core holes 14a-b formed in the guard arm side. The core hole pairs, 12a-b and 14a-b respectively, are interconnected to provide passages underneath central region 16 and are divided from each other by a rib 18. The core holes 12a-b and 14a-b were not originally designed to serve any function on the finished coupler head 10; rather, they facilitated casting. Nevertheless, the industry has recognized that the core holes are good locations for securing end-of-train signaling and monitoring equipment and several railroad coupler mounts have been devised which take advantage of them. For example, U.S. Pat. No. 4,520,662 to Schmid shows a coupler mount with four opposing jaw members which grip within the four core holes 12a-b and 14a-b in the coupler head 10. The disadvantage of the Schmid device is that it is heavy and complicated and, therefore, difficult for a single person to install on the coupler head 10. U.S. Pat. No. 4,691,563 to Martin et al. and U.S. Pat. No. 4,876,885 to Martin et al. each describe railroad coupler mounts which include a banana-shaped arm that extends through a core hole pair 12a-b or 14a-b, respectively. Further, U.S. Pat. No. 5,235,849 to Egerton shows a railroad coupler mount that includes a hook for contacting the inside upper lip of a coupler head within a single coring hole, a jaw member which engages the rib between a pair of coring holes, a pad for abutting against an outside surface of the coupler head, and a handle for orienting the hook in the transverse or upright positions. However, in some instances where the core hole is small, the Egerton device has the drawback that the end-of-train equipment may not be temporarily hooked within that small single coring hole of the coupler head. In particular, if the hole is small enough to require that the hook be oriented in a substantially horizontal position in order to insert the hook within the hole, then the hook must first be rotated to temporarily hook within the hole prior to final tightening. While the Martin et al. and Egerton devices are easier to mount, there is still a need for alternative railroad coupler mounts which provide easy yet secure clamping of the end-of-train signaling and monitoring equipment from with the core holes in the coupler head of the last car of the train. In particular, a need exists for an alternative coupler mount which is easily transported and installed by one person and which may hang temporarily from within a randomly sized core hole prior to tightening during installation.